Automated linear vacuum distribution valve

Abstract

Aspects of a system for holding workpieces in place during processing are described. In an example, the system includes a distribution manifold coupled to a vacuum source, and multiple linear valves coupled to the distribution manifold, where each linear valve has a manifold with multiple openings and is adjustable to select one or more of the multiple openings to have a path to the vacuum source through the distribution manifold for providing a vacuum to hold a workpiece in place. In another example, the system includes a vacuum holder having a first array of openings, a system of linear valves positioned below the vacuum holder and having a second array of openings that aligns with the first array of openings, and a vacuum source that provides vacuum for holding a workpiece on the vacuum holder. A method for holding workpieces in place during processing using these systems is also described.

What is claimed is: 
     
         1 . A system for holding workpieces in place during processing, comprising:
 a distribution manifold coupled to a vacuum source; and   multiple linear valves coupled to the distribution manifold, each linear valve having a manifold with multiple openings and being adjustable to select one or more of the multiple openings to have a path to the vacuum source through the distribution manifold for providing a vacuum to hold one or more of the workpieces in place.   
     
     
         2 . The system of  claim 1 , wherein the multiple linear valves are positioned adjacent to each other and under a vacuum chuck or a vacuum table on which the workpieces are held in place by vacuum provided by the vacuum source through the one or more of the multiple openings in each of the linear valves that have a path to the vacuum source. 
     
     
         3 . The system of  claim 2 , wherein the multiple openings of the multiple linear valves are collocated with multiple openings in the vacuum chuck or the vacuum table. 
     
     
         4 . The system of  claim 1 , wherein each linear valve includes a leadscrew and a piston both disposed inside the manifold, the piston being moved along a length of the manifold by rotation of the leadscrew to select the one or more of the multiple openings in the manifold when the linear valve is adjusted. 
     
     
         5 . The system of  claim 4 , further comprising a motor associated with each linear valve and configured to adjust the linear valve by driving the rotation of the leadscrew and thereby moving the piston along the length of the manifold. 
     
     
         6 . The system of  claim 5 , wherein the motor is an indexable motor. 
     
     
         7 . The system of  claim 4 , wherein a cross-sectional shape of the manifold is configured to match a shape of the piston to prevent rotation of the piston with respect to the leadscrew. 
     
     
         8 . The system of  claim 4 , further comprising a motor coupling that mechanically couples the motor and the leadscrew for the associated linear valve. 
     
     
         9 . The system of  claim 4 , wherein:
 each linear valve is configured to be have the piston moved by the rotation of the leadscrew to a first position within the manifold such that only a first subset of the multiple openings in the manifold has a path to the vacuum source, and subsequently to a second position within the manifold such that only a second subset of the multiple openings in the manifold has a path to the vacuum source, and   the first subset of the multiple openings is different from the second subset of the multiple openings.   
     
     
         10 . The system of  claim 9 , wherein a number of openings in the first subset of the multiple openings is different from a number of openings in the second subset of multiple openings. 
     
     
         11 . The system of  claim 9 , wherein the openings in the first subset of the multiple openings are contiguous and the openings in the second subset of the multiple openings are contiguous. 
     
     
         12 . The system of  claim 1 , wherein:
 the manifold is an elongated member having a proximal end and a distal end, and   the distribution manifold is also an elongated member positioned across the multiple linear valves and coupled to the proximal end of the manifold of each linear valve to provide a path to the vacuum source.   
     
     
         13 . The system of  claim 12 , further comprising a motor associated with each linear valve, wherein the motor is coupled to the distal end of the manifold of the linear valve. 
     
     
         14 . The system of  claim 1 , wherein the manifold in each linear valve has a square cylindrical shape. 
     
     
         15 . The system of  claim 1 , wherein the workpieces include optoelectronic devices. 
     
     
         16 . The system of  claim 15 , wherein the optoelectronic devices include photovoltaic devices. 
     
     
         17 . A system for holding workpieces in place during processing, comprising:
 a vacuum holder having a first array of openings;   a system of linear valves positioned below the vacuum holder and having a second array of openings that aligns with the first array of openings; and   a vacuum source to provide a vacuum for holding one or more of the workpieces on the vacuum holder, wherein:
 the system of linear valves includes multiple linear valves and a distribution manifold coupled to the vacuum source and to the multiple linear valves, each linear valve including a manifold with multiple openings, each linear valve being adjustable to select one or more of the multiple openings in the manifold to have a path to the vacuum source through the distribution manifold, and the second array of openings including the multiple openings of the manifolds of the multiple linear valves. 
   
     
     
         18 . The system of  claim 17 , wherein the multiple linear valves are configured to be individually adjusted to select a subset of the second array of openings for providing the vacuum. 
     
     
         19 . The system of  claim 17 , wherein the subset of the second array openings is selected based on a size of the one or more of the workpieces to be held on the vacuum holder. 
     
     
         20 . The system of  claim 17 , wherein the multiple linear valves are configured to be individually adjusted to select a first subset of the second array of openings for providing the vacuum to hold one of the workpieces and to subsequently select a second subset of the second array of openings for providing the vacuum to hold an additional one of the workpieces. 
     
     
         21 . The system of  claim 17 , wherein each linear valve includes a leadscrew and a piston both disposed inside the manifold, the piston being moved along a length of the manifold by rotation of the leadscrew to select the one or more of the multiple openings in the manifold when the linear valve is adjusted. 
     
     
         22 . The system of  claim 21 , further comprising a motor associated with each linear valve and configured to adjust the linear valve by driving the rotation of the leadscrew and thereby moving the piston along the length of the manifold. 
     
     
         23 . The system of  claim 22 , wherein the motor is an indexable motor. 
     
     
         24 . The system of  claim 17 , wherein the vacuum holder one or more of a vacuum chuck, a vacuum table, or a top plate. 
     
     
         25 . The system of  claim 17 , wherein the multiple linear valves are adjacently positioned such that the multiple openings in their respective manifolds are arranged to form the second array of openings. 
     
     
         26 . The system of  claim 17 , wherein the second array of openings is aligned with the first array of openings such that vacuum applied through one of the openings in the second array of openings is applied through a corresponding opening in the first array of openings. 
     
     
         27 . The system of  claim 17 , wherein the workpieces include photovoltaic devices. 
     
     
         28 . A method for holding workpieces in place during processing, comprising:
 providing a system of linear valves positioned below a vacuum holder on which one or more of the workpieces are placed during processing, the vacuum holder having a first array of openings and the system of linear valves having a second array of openings aligned with the first array of openings;   dynamically selecting a subset of openings from the second array of openings for which a path to a vacuum source is to be provided by adjusting one or more of multiple linear valves included in the system of linear valves, the subset of openings from the second array of openings being selected based on a number of the workpieces to be held in place on the vacuum holder; and   applying a vacuum provided by the vacuum holder through the subset of openings from the second array of openings and through their respective openings in the first array of openings in the vacuum holder.   
     
     
         29 . The method of  claim 28 , wherein adjusting the one or more of multiple linear valves included in the system of linear valves includes adjusting, for at least one of the linear valves, a position of a piston within a manifold of each linear valve to enable one or more openings in the manifold of that linear valve to be part of the subset of openings and have a path to the vacuum source while remaining openings in the manifold of that linear valve are isolated from the vacuum source. 
     
     
         30 . The method of  claim 29 , wherein adjusting the position of the piston within the manifold includes rotating a leadscrew to move the piston along the length of the manifold to the position, the leadscrew being rotated by running a motor coupled to the leadscrew. 
     
     
         31 . The method of  claim 28 , wherein dynamically selecting the subset of openings from the second array of openings for which a path to the vacuum source is to be provided includes increasing a number of openings selected for the subset of openings from the second array of openings when additional workpieces are to held in place for processing. 
     
     
         32 . The method of  claim 28 , further comprising disabling the application of the vacuum when the processing is completed and returning the multiple linear valves included in the system of linear valves to a default position. 
     
     
         33 . The method of  claim 28 , wherein the workpieces include photovoltaic devices.